DNA and Genetics

Question 1

reproduction

Answer 1

• asexual reproduction (no mate, clones of parent)
• sexual reproduction (fusion of male and female gametes (sex cells)

Question 2

gametes

Answer 2

produced through meiosis

Question 3

process of gamete fusion

Answer 3

creates the zygote (first cell of offspring) then develops to the embryo and foetus

Question 4

male reproductive system

Answer 4

• testis - male gonads contain sperm storage in the epididymis, location of testosterone synthesis
• scrotum - sac containing the testes
• vas deferens - sperm duct, connects to the urethra
• cowper’s gland, seminal vessel and prostate gland add fluid to sperm, forming semen

Question 5

gonads

Answer 5

glands that produce reproductive hormones

Question 6

female reproductive system

Answer 6

• ovary - female gonads, location of ova storage
• fallopian tube - (oviducts) connect each ovary to the uterus
• uterus - the womb, muscular organ lined with endometrium
• vagina - muscular canal with opening, cervix

Question 7

traits

Answer 7

the physical characteristics and behaviors of an organism (inherited or learnt)

Question 8

genes

Answer 8

segments of DNA that code for traits
- can be turned off and on per environmental factors
- contains instructions for constructing parts of proteins

Question 9

homozygous

Answer 9

two of the same, homozygous dominant/recessive

Question 10

hetrozygous

Answer 10

a copy of each allele

Question 11

genotype and phenotype

Answer 11

the pair of alleles
the physical expression of the genotype

Question 12

DNA

Answer 12

• a chemical found in the nucleus of most cells
• deoxyribonucleic acid
• contains segments of genes
• polymer composed of 2 strands of nucleotides

Question 13

4 nitrogen bases of nucleotides

Answer 13

• adenine
• cytosine
• guanine
• thymine
  (cytosine + guanine, adenine + thymine)

Question 14

genome

Answer 14

all of the dna in an organism

Question 15

dna no.s in humans

Answer 15

DNA is coiled into 23 pairs of chromosomes total of 46
- 22 pairs somatic
- 1 pair sex chromosomes

Question 16

homologous chromosomes

Answer 16

result of sexual reproduction, 2 copies of the same chromosome

Question 17

diploid organisms

Answer 17

contain 2 copies of each chromosome

Question 18

forms of proteins

Answer 18

• enzymes - act as biological catalysts
• hormones - chemical messengers
• transport - carries oxygen to cells and carbon dioxide away
• structural - form tissues
• contractile - allow movement through muscle contraction
• motor - produce mechanical movement
• antibodies - proteins that play an important role in the immune system

Question 19

amino acids

Answer 19

small organic molecules that are the components of proteins

Question 20

codon/triplet

Answer 20

three nucleotides in a row
- given instructions as to which amino acid to code for
- 1 start codon and 3 stop codons in an amino acid

Question 21

cell cycle

Answer 21

DNA is replicated into 2 daughter cells

Question 22

why do cells reproduce?

Answer 22

• growth and repair
  cells need to be replace due to damage or age and in growth. (creating new cells in somatic cells is mitosis)
• reproduction
  cell replication to create gametes via meiosis

Question 23

2 main types of cells in the human body

Answer 23

• gametes - sex cells
• somatic cells - no sex cells :)

Question 24

steps of mitosis

Answer 24

1. membrane of nucleus breaks down to condense chromosomes
2. chromosomes lined up down the middle of the cell (made up of two parts called chromatids)
3. sister chromatids pulled apart to each pole of the cell
4. cytokinesis - the cell divides

Question 25

meiosis

Answer 25

• 2 rounds of mitosis and cell division
• 4 gametes are produced and are not identical
• gametes are haploid (single set of chromosomes)
• only occurs in the gonads

Question 26

mutations

Answer 26

changes to the genetic code
can occur during DNA replication before cell division protein synthesis

Question 27

3 outcomes of mutations

Answer 27

• silent mutations, DNA change doesn’t effect the expressed amino acid
• abnormal change/function - changes function of the protein
• favourable change

Question 28

mutagens

Answer 28

cause mutations, can naturally occur or synthetic. can cause uncontrolled cell growth and division

Question 29

types of mutagens

Answer 29

• electromagnetic radiation
• chemical mutagens
• naturally occurring mutagens