Genetics

Question 1

What is DNA?

Answer 1

Deoxyribonucleic acid, it is located in the nucleus, this is what contains genetic information

Question 2

What is RNA?

Answer 2

Ribonucleic acid there are 3 types:
mRNA
tRNA
rRNA

Question 3

What are A, T, C, and G and what do they stand for / match up with

Answer 3

Adenine 
Thymine
Cytosine 
Guanine 
C with G 
A with T

Question 4

What are purines?

Answer 4

Part of the DNA structure, they have a double ring structure

Question 5

What are pyrimidines?

Answer 5

Part of the DNA structure, they have a single ring structure

Question 6

What are nitrogenous bases connected by?

Answer 6

Hydrogen bonds

Question 7

Which way do DNA strands run?

Answer 7

Anti-parallel

Question 8

What is a nucleotide?

Answer 8

part of the DNA structure, they are made of sugar, they are bonded by a phosphate bond & nitrogen bond

Question 9

What is a gene?

Answer 9

Section of DNA responsible for inheriting particular characteristics

Question 10

What are the 2 main parts of the cell cycle?

Answer 10

Interphase and mitosis

Question 11

What is Mitosis?

Answer 11

Cell division that results in the production of 2 identical daughter cells

Question 12

What are the stages of mitosis? (4)

Answer 12

1. Prophase: chromatin coils to form visible chromosomes
2. Metaphase: chromosomes move to the equator of the cell
3. Anaphase: the centromeres split and sister chromatids are pulled apart to to the opposite poles of the cells
4. Telophase: two daughter cells are formed and the cells divide

Question 13

What is Meiosis?

Answer 13

produces reproductive cells called gametes (egg and sperm) essentially mitosis twice

Question 14

What are gametes?

Answer 14

Egg and sperm cells (reproductive) they are haploid (n), they contain 1/2 the number of chromosomes (eg there are 46 in humans so their would be 23 in each haploid)

Question 15

What are the stages of meiosis I?

Answer 15

Prophase I: nucleur membrane and nucleolus disappear and spindle fibres form, similar chromosomes match up (homologous chromosomes) - made up of 4 chromatid known as tetrad

Metaphase I: the pairs of chromosomes line up along the equator randomly (independent assortment) this is synapsis

Anaphase I: the homologous chromosomes separate and move to opposite poles, this is disjunction

Telophase I: the spindle disappears, nuclear membrane reforms, cytokinesis occurs,

Question 16

What are the stages of Meiosis II?

Answer 16

identical to mitotic cell division (PMAT)

Question 17

What is the end result of meiosis?

Answer 17

4 non-identical daughter cells, meiosis I has a diploid of chromosomes (46), meiosis II has a haploid set of chromosomes (23) GAMETOGENESIS (the production of gametes)

Question 18

Male gametes

Answer 18

produced by spermatogenesis, the sperm only have a nucleus and flagellum

Question 19

Female gametes

Answer 19

produced by oogenesis: only one cell becomes a viable sex cell

Question 20

What is genetic variation?

Answer 20

1. during prophase I the tips of non-sister chromatids may cross over during synapsis and exchange genetic information
2. during metaphase I homologous chromosomes independently assort to form tetrads

Question 21

Genetics

Answer 21

the scientific study of inheritance

Question 22

Heredity

Answer 22

the transmission of characteristics from one generation to the next

Question 23

Allele

Answer 23

the particular DNA form that appears at the gene location for an inherited characteristic

Question 24

Homologous chromosomes

Answer 24

pairs of chromosomes that carry corresponding DNA codes (1 from mom, 1 from dad)

Question 25

Homozygous

Answer 25

refers to an offspring that receives 2 identical alleles for a given gene location

Question 26

Who was Gregor Mendel?

Answer 26

"Father of genetics"

Question 27

What is the principle of segregation?

Answer 27

when an allele from a parent sorts into a separate gamete

Question 28

what is a dominant trait?

Answer 28

when a characteristic is always expressed, or always appears in an individual

Question 29

what is a recessive trait?

Answer 29

when a characteristic is present, but may not be expressed except in homozygous form

Question 30

What is the law of dominance?

Answer 30

if an organism is heterozygous one trait will always be dominant

Question 31

What is the law of independent assortment?

Answer 31

offspring can have new combinations of genes that were not present in the parents

Question 32

What is incomplete dominance?

Answer 32

when both alleles contribute to the phenotype of the heterozygous individual, aka blending inheritance. Neither of the alleles hides the presence (think white + red makes pink)

Question 33

What is codominance?

Answer 33

two alleles are expressed at the same time capital letters with superscripts are used to demonstrate this (think roan colour in cattle)

Question 34

What are multiple alleles?

Answer 34

eg. of codominance and dominant / recessive genetics, there are more than 2 possible alleles.

Question 35

What are the rules of bloodtypes?

Answer 35

I^A and I^B are dominant to i I^A and I^B are codominant to eachother ii is recessive

Question 36

What is polygenetic inheritance?

Answer 36

is controlled by 2 or more genes, each with 2 alleles, so there is a wide variation eg. skin and eye colour

Question 37

What are lethal genes?

Answer 37

they are alleles that can lead to the death of the organism, may be dominant or recessive, they control more then 1 phenotype

Question 38

What are autosomal chromosomes?

Answer 38

22 of the 23 pairs of chromosomes that aren't related to gender

Question 39

What are sex chromosomes?

Answer 39

the last pair of chromosomes responsible for determining the gender of the offspring, x is girl, y is boy

Question 40

What is a karyotype?

Answer 40

diagram or photograph of somatic chromosomes

Question 41

What are the rules of a pedigree?

Answer 41

men are square women are circle people showing a characteristic are solid colour women who are carriers have half of the circle shaded in

Question 42

Genetic mutations

Answer 42

an error in the DNA sequence | may also be seen at the chromosomal level

Question 43

What are the chromosomal mutations? (4)

Answer 43

1. delection - a portion of chromosome is lost 2. Duplication - a portion of the chromosome is added 3. inversion - a portion of the chromosome is inverted 4. translocation - a portion of the chromosome is switched with another