Exam: Genetics

Question 1

What are the gs cell theory states

Answer 1

All living things are composed of one or more cells
All cells come from or existing cells
Cells are the simplest unit of living organisms

Question 2

Difference between chromatin, chromatid, centromere

Answer 2

Chromatin - DNA
Chromatid - half a chromosome
Centreomete - holding chromatids together

Question 3

What are the three stages of interphase

Answer 3

G1- majour phase of growth
S - DNA replication
G2 - secondary growth phase

Question 4

Mitosis: describe PMAT

Answer 4

Prophase: everything is getting ready to split
Metaphase: all chromosomes go in the middle
Anaphase: split into sister chromatids
Telophase: Chromosomes reach opposite poles of cell and unravel

Question 5

What is cytokinesis

Answer 5

Takes place after telophase, equal division of cytoplasm and organelles among daughter cells and forms a cleavage furrow.

Question 6

How many chromosomes do we have in our body

Answer 6

46 (22 diploids, 2 sex)

Question 7

What is meiosis

Answer 7

Basically mitosis but interkinase only happens once and first it’s diploids then turns into haploids. 4 divisions instead of 2

Question 8

Purpose of mitosis

Answer 8

To grow, Regenerate and maintenance. This takes place throughout life in the somatic cells

Question 9

Purpose of meiosis

Answer 9

To produce gametes with each of of parents genetics .Takes place during puberty in the gamete cells.

Question 10

What is abnormal meiosis

Answer 10

Chances in number or structure

Question 11

What is deletion in a chromosome

Answer 11

A piece of chromosome is lost

Question 12

What is duplication in chromosome

Answer 12

Section of a chromosome appears two or more times in a row

Question 13

What is Inversion in a chromosome

Answer 13

Segment of DNA in a chromosome flips upside down, no information is lost

Question 14

What is translocation in a chromosome

Answer 14

Non homologous chromosomes cross over

Question 15

What is nondisjunction

Answer 15

Improper separation or a fail to separate during meiosis

Question 16

When does non disjunction happens

Answer 16

Anaphase I or Anaphase II.

Question 17

What are the two results on nondisjunction

Answer 17

Monosomy= single pair
Trisomy= three pairs

Question 18

What is Trisomy 21

Answer 18

Down syndrome

Question 19

What is Trisomy 18

Answer 19

Edward syndrome,

Question 20

Trisomy 13

Answer 20

Patan syndrome

Question 21

What is XXY

Answer 21

Kilnefelter (can’t produce sperm)

Question 22

What is XYY

Answer 22

Jacobs (taller than average)

Question 23

What is XXX

Answer 23

Triple X (tall and thin with irregular mentrual cycle)

Question 24

What is XO

Answer 24

Turner (short statue, webbed feet, sexually underdeveloped)

Question 25

What is a ultrasound

Answer 25

Non invasive Visual image of body through sound waves

Question 26

What is a multiple marker screen

Answer 26

Non invasive Blood test and ultrasound at 15-20 weeks. Check mothers blood for tube defects. Tests 21 and 18

Question 27

What is Aminocentesis

Answer 27

Inavise needle to uteri’s to extract amniotic fluid. 1% chance of miscarriage. Tests everything.

Question 28

What is chorionic villi sampling

Answer 28

Invasive sampling of placenta to take out chorionic villi. 1% miscarriage. Tests for everything

Question 29

What is a genotype

Answer 29

The genetic combination of a gene

Question 30

What is a phenotype

Answer 30

Things seen visually on a person

Question 31

What is true breeding

Answer 31

When parents give homologous traits to the child