Lecture 1

Question 1

what is human genetics

Answer 1

the study of human variation

Question 2

medical genetics

Answer 2

the study of genetic disease in humans

Question 3

clinical genetics

Answer 3

a medical specialty which deals with families affected by or at risk of genetic disease

Question 4

what are the two major foundations of modern genetics

Answer 4

• Darwins theory of evolution
• Mendel’s laws of heredity

Question 5

Mendel’s Laws

Answer 5

1. law of uniformity
2. law of segregation
3. law of independent assortment

Question 6

homozygote

Answer 6

an organism that carries two identical alleles for a particular gene

Question 7

explain the law of uniformity

Answer 7

when 2 homozygotes for different alleles are crossed, all of the F1 offspring are identical and heterozygous

during the formation of gametes, the two alleles (variants of a gene) for each trait separate
from each other so that each gamete receives only one allele for each trait. As a result, offspring inherit one allele from each parent.

Question 8

explain the law of segregation

Answer 8

each individual possesses 2 genes for each characteristic only one of which can be transmitted at any one time

Question 9

explain the law of independent assortment

Answer 9

members of different gene pairs segregate to offspring independently of one another

Question 10

eugenics

Answer 10

the improvement of a population genetic constitution by selective breeding

Question 11

how are genes carried

Answer 11

genes are carried by chromosomes which are present in the nucleus of every cell

Question 12

mitosis

Answer 12

form of replication in all non-gonadal cells.
cell replicates to form two identical copy cells, each with the same number of diploid number of chromosomes

Question 13

meiosis

Answer 13

form of cell division which produces gametes
in humans this form of division produces 23 chromosomes gametes from 46 chromosomes parent cells

Question 14

what are the stages of mitosis

Answer 14

interphase: DNA replication

prophase: chromosomes condense

metaphase: chromosomes align in center and attach to spindle

anaphase: move along spindles to opposite poles

telophase: the divides into two daughter cells

Question 15

at what stage is best for looking at the chromosomes

Answer 15

metaphase

Question 16

what are the two cell divisions that meiosis involves

Answer 16

meiosis 1 - the reduction division

meiosis 2 - a simple mitotic reduction, with the same stages as mitosis

Question 17

what is the formation of ova called

Answer 17

oogenesis

Question 18

what is the formation of sperm called

Answer 18

spermatogenesis

Question 19

when does oogenesis occur

Answer 19

prior to birth in the developing foetal ovaries

Question 20

dictyotene stage

Answer 20

the prophase kind of stops
they remain in this phase until ovulation occurs up to 50 years later

Question 21

when is meiosis II complete

Answer 21

after fertilisation in the Fallopian tube, when the secondary oocyte divides into an ovum and a polar body