RNA, DNA, GENES, AND CHROMOSOMES PRACTICE QUESTIONS

THE CELL STRUCTURE AND FUNCTION

Functions of some cell organelle:

1.      Nucleus: Control center of the cell. Contains DNA which directs the synthesis of  

      proteins by the cell.

2.      Mitochondria: Carries on the process of cell respiration by converting glucose to 

      ATP energy.

3.  Ribosome: Found on the endoplasmic reticulum and free within the cell. 

Responsible for the synthesis of proteins for the cell.

4.  Endoplasmic reticulum: Transport channels within the cell.

5.  Food vacuole: stores and digests food.

6.  Lysosomes: Contain digestive enzymes. Breaks down substances in the cell.

7. Contractile vacuoles: Pumps out wastes and excess water from the cell.

8.  Cell membrane: Selectively regulates the materials moving to and from the cell.

 9.  Chloroplast: Found only in plant cells and algae. Contains chlorophyll (the green   

     coloring substance in plants) which carries on the process of photosynthesis.

10. Cell wall: Surrounds and supports plant cells. Only in plants. The cell wall is formed  

     from the cell plate during cell division.

EXAM TIPS:

• If you see centriole and centrosome in a question, think of an animal cell. They occur only in animal cells and they are involved in cell division where they produce spindles.
•  If you see cell plate and chloroplasts in a question, think of a plant cell. They occur only in plant cells.

TEST YOUR KNOWLEDGE

1. A student was looking at a cell under the microscope and noticed that centrosomes were present. Which   type of cell was the person looking at?
       A. Bean cell
       B. Carrot cell
       C. Cat cell
       D. Cabbage cell

2. A certain drug inhibited the production of adenosine triphosphate (ATP). This drug acted on which of the  following organelle?
       A. Endoplasmic reticulum
       B. Nucleus
       C. Mitochondrium
       D. Ribosmes

3. A student was looking at a cell under the microscope and noticed that chloroplasts were present. Which  type of cell was the person looking at?
       A. Dog cell
       B. Mouse cell
       C. Cat cell
       D. Cabbage cell

4. Nucleus is to DNA as chloroplast is to _________________ .
       A. RNA
       B. Plant
       C. ATP
       D. Chlorophyll

5. The genetic blueprint of life can be found in which of the following structure?
       A. Endoplasmic reticulum
       B. Nucleus
       C. Mitochondrium
       D. Ribosmes

6. Which of the following is not involved in protein synthesis?
      A. Endoplasmic reticulum
       B. Nucleus
       C. Mitochondrium

       D. Ribosmes

Answers: 
1. C. Cat cell (Centrosomes occur only in animal cells)
2. C. Mitochondrium (Mitochondrium is involved in ATP production so inhibiting it will lead to decreased production)
3. D. Cabbage cell (Chloroplast is found only in plant cells)
4.  D. Chlorophyll
5. B. Nucleus (Nucleus contains the DNA, the genetic blueprint of life)

6. C. Mitochondrium

THE ENDOCRINE SYSTEM

An endocrine gland is a gland without ducts. The secretions are released directly into the blood. The endocrine glands secrete hormones that regulate various metabolic activities in the body.
Here is a good diagram of the endocrine system. Click here. You can be given a diagram like this and you could be asked to identify the various glands.

Hypothalamus: The hypothalamus produces eight (8) hormones. Some of the hormones stimulate the pituitary gland to produce other hormones.

1. Thyrotropin-releasing hormone - This acts on the pituitary to release thyroid stimulating hormone (TSH)
2. Growth hormone-releasing hormone-This acts on the pituitary to release growth hormone (GH)
3. Gonadotropin-releasing hormone -This acts on the pituitary to release gonadotropins, namely, Follicle stimulating hormone (FSH) and Luteinizing hormone (LH).
4. Corticotropin-releasing hormone -This acts on the pituitary to release adrenocorticotropic hormone.
5. Oxytocin -This causes uterine contractions and also helps with secretion of the breast milk during lactation.
6. Dopamine - It is a neuroendocrine transmitter. Acts as a neuro-transmitter and also stimulates the release of othe hormones.
7. Vasopressin (Antidiuretic hormone -ADH) - Acts on the kidneys to prevent the lost of water via the urine.
8. Somatostatin - It inhibits the release of growth hormone.

Pituitary gland: Has an anterior (hormone-producing glandular) portion and a posterior (neural) portion which is an extension of the hypothalamus.  Two hormones ( Oxytocin and ADH) produced by the hypothalamus are stored in the posterior pituitary later release.

Four of the six pituitary hormones are tropic hormones. They regulate the function of other endocrine glands.Here are the hormones produced by the anterior portion:

1.  Growth hormone (GH): It stimulates growth of all body tissues but especially skeletal muscle and bone. GH mobilizes fats, stimulates protein synthesis, and inhibits glucose uptake and metabolism. Over production can lead to gigantism while underproduction can lead to dwarfism.

2. Thyroid-stimulating hormone (TSH): This promotes normal development and activity of the thyroid gland. 

3. Adrenocorticotropic hormone (ACTH): This stimulates the adrenal cortex to release  corticosteroids. 

4. The gonadotropins (follicle-stimulating hormone (FSH) and luteinizing hormone (LH)): These regulate the functions of the gonads in both sexes. 

     (a) FSH stimulates sex cell production.  

     (b) LH stimulates gonadal hormone production. 

5. Prolactin (PRL): This promotes milk production in humans females. 

The posterior portion stores and releases two hypothalamic hormones:

1. Oxytocin: This stimulates powerful uterine contractions during labor and delivery of babies. It also causes milk ejection in nursing women. 

2. Antidiuretic hormone (ADH): This stimulates the kidney tubules to reabsorb and conserve water. This results in the production of small volumes of highly concentrated urine and decreased plasma osmolality. Underproduction leads to a condition called diabetes insipidus, where the affected person passes a lot of diluted urine.

Thyroid gland

It produces the thyroid hormone (TH), which includes thyroxine (T4) and triiodothyronine (T3). It increases the rate of cellular metabolism. 

Calcitonin, is produced by the parafollicular cells of the thyroid gland. It decreases the blood calcium levels.

Parathyroid glands

It secretes parathyroid hormone (PTH), which causes an increase in blood calcium levels.

Pancreas

The pancreas is both an exocrine and an endocrine gland. Exocrine means that it has ducts. The endocrine portion (islets of langerhans) releases insulin and glucagon. It also releases smaller amounts of other hormones to the blood.

Glucagon, released by alpha (α) cells - It increases the glucose level in the blood.

Insulin is released by beta (β) cells - It reduces the glucose level in the blood. It increases the rate of glucose uptake and metabolism by most body cells. 

Gonads

The ovaries of the female release two main hormones - estrogens and progesterone. Estrogens stimulate maturation of the female reproductive system and development of the secondary sexual characteristics. Progesterone works with estrogens in establishing the menstrual cycle.

The testes of the male produce testosterone. It promotes maturation of the male reproductive organs, development of secondary sex characteristics, and production of sperm by the testes.

Pineal gland

The pineal gland produces the hormone  melatonin, which influences daily rhythms such as sleep and wake patterns.

Thymus 
It is an important organ of the immune system during the developmental stages of life. It vanished by the time of birth. The T-cells mature here.

OVERVIEW OF THE LYMPHATIC SYSTEM

RESOURCES: PREPARING FOR NURSING ENTRANCE EXAMS

TERMS AND DEFINITIONS YOU CANNOT AFFORD NOT TO KNOW

HOW MUCH DO YOU KNOW ABOUT CELL STRUCTURE AND FUNCTION

The basic unit of the living organism is the cell. To pass the test, you must know the functions of the cell organelles very well. You must know the difference between the animal and plant cell.
You can review the cell structure and functions from the past lessons and then proceed to the multiple choice questions to test your skills. Click here to review the lesson.

Here is a link to practice on questions related to the cell structure and functions.

HOW TO ACE THE PRE-NLN ENTRANCE EXAM

HOW TO STUDY FOR NURSING ENTRANCE EXAMS

Preparing for any exam requires adequate preparation and strategies. This video highlights how you can strategically prepare for nursing entrance exams such as Pre-NLN, TEAS, Kaplan, and HESI. If you deligently follow the laid out strategies, we will definitely suceed on the exam.

TOP-NOTCH BLOGS FOR NURSING ENTRANCE EXAMS