Mod 5

Question 1

Define fertilisation

Answer 1

union of male and female gametes.

Question 2

Haploid

Answer 2

male and female gametes unite to produce genetically unique diploid (2n) offspring.

Question 3

(n)

Answer 3

A haploid

n = 23

Question 4

Zygote

Answer 4

A diploid.

Question 5

The characteristic amount of chromosones in humans cells.

Answer 5

46

Question 6

Meiosis

Answer 6

the cell division that is the mechanism that ensures each parent contributes only half the genetic information required.
When it divides, it contains only ONE SET of chromosomes.

Question 7

Plants asexual reproduction method examples

Answer 7

BULBS: onion

• underground bud cells
• short stem surrounded by leaves

RUNNERS: strawberries

• side chains
• A stem that extends from the plant along the soil.
• Allows the formation of a new plant in another area.
• eg. Strawberries.

Question 8

Fungi reproduction method examples

Answer 8

BUDDING: yeast

• A bulge forms from the side of a cell and detaches after the nucleus divides
• An asexual spore genetically indenticle to the parent is formed.

SPORES
- undergo mitotic division to produce the multicellular organism.

Question 9

Bacteria reproduction method examples

Answer 9

BINARY FUSSION:‘Thermus bacteria’

A single cell divides into two genetically identical daughter cells.

Question 10

Difference between ovarian cycle and Menstrual cycle.

Answer 10

Ovarian Cycle: Governs the release of an egg.

Menstrual cycle: Governs the preparation and maintenance of the uterine lining.

BOTH: 28 days, involved in the hormonal control during pregnancy.

Question 11

Role of hormones during pregnancy

Answer 11

Hormones…
Provide an ideal environment for pregnancy; important for growth and long term health.
Prevent overgrowth.
Inhibit fetus growth (at particular stages).

Question 12

Role of mitosis

Answer 12

• Growth in multicellular organisms.
• Repair & replacement of damaged cells.
• Asexual reproduction purposes.
• Genetic stability: (equal distribution of chromosomes to daughter cells.)
• Replication of bodily cells.

Question 13

Site of mitosis

Answer 13

Stem cells: specialised cells CANNOT undergo mitosis, thus they rely on stem cells. For example: plant guard cells, stomata, cells involved in the human nervous system cannot duplicate themselves.

Question 14

Stages in mitosis

Answer 14

• (interphase)
• prophase
• metaphase
• anaphase
• telophase
• cytokinesis

Question 15

Chromosomes

Answer 15

A long DNA molecule coiled tightly to store genetic information.

Question 16

Sister chromatids

Answer 16

2 copies of a single chromosome, being genetically identical. Held together by a centrosome.

Question 17

Chromatid

Answer 17

Either of the two daughter cells of the duplicated chromosomes joined by a centriole

Question 18

Spindle fibres

Answer 18

Cytoskeleton/protein structures that divide genetic material.

Question 19

Meiosis

Answer 19

• Reduction division in cells to produce gametes.
• Produces haploid cells: 4 non-identical cells.
• Contains half the needed amount of chromosomes.

Question 20

Meiosis role

Answer 20

In sexual reproduction
Ensure the needed number of chromosomes is maintained.
Introduces genetic variation: the law of independent assortment, crossing over.

Question 21

(list) the role of cell replication in the continuity of a species

Answer 21

Genetic stability: lineage of desirable traits.

Genetic variation: the opportunity for mutation, survival advantages, crossing ver.

Question 22

Rosalin Franklin

Answer 22

Determined the double helix structure of DNA
Ran antiparallel.
Used crystallography techniques such as Xray to show DNA to be a spiral.
Was not credited.

Question 23

(list) Watson and Crick Discoveries

Answer 23

• Nucleotide bonding & pairing.
• Nucleotide composition
• DNA replication

Question 24

Steps in DNA replication & enzyme

Answer 24

• Initiation: helicase
• Elongation: RNA primer, DNA polymerase
• Termination: DNA polymerase, terminator.

Question 25

DNA:

Answer 25

double-stranded twisted helix that holds all the genetic information necessary for CELLULAR FUNCTION, GROWTH and DEVELOPMENT.

Question 26

Role of mitochondrial and chloroplast DNA

Answer 26

Produce proteins required for function.

Question 27

Mitochondrial DNA

Answer 27

mtDNA = mitochondrial DNA Holds DNA separate from nucleic DNA. Double-stranded, circular molecule, NO introns. Contains 37 genes. More consistent, undergoes less change than nucleic DNA HIGH lineage. Replicate own DNA

Question 28

Introns

Answer 28

a segment of a DNA or RNA molecule which does not code for proteins and interrupts the sequence of genes.

Question 29

Chloroplast DNA

Answer 29

cpDNA = chloroplast DNA. Double stranded, circular molecule, NO introns. Contains up to 150 different genes. Replicate your own DNA.

Question 30

Amino acids

Answer 30

Amino acids: building block for proteins

Question 31

Define gene expression and environmental factors that affect it.

Answer 31

the use of information provided by a gene to produce a protein. Womb Diet Climate Surroundings Disease Example: any differences observed in identical twins are due to environmental factors.

Question 32

Similarities between meiosis and mitosis

Answer 32

Both break down nucleic material to from spindles The phases are named the same Both undergo interphase The transformation of chromatin material to chromosomes during prophase is the same.

Question 33

Mendles laws

Answer 33

Autosomal inheritance: the genotype of a trait is affected by 2 genes, equally as likely to be inherited by either parent. 1. dominance and segregation: Recessive alleles will always be masked by dominant alleles 2. the law in independent assortment: The alleles of two or more different genes are sorted into gametes separately from one another, being influenced by previous gametes received. Eg. mendel: the pea plants crossed different pairs of patterns eg (tall/short, yellow/green).

Question 34

(list) deviations to mendles law with examples

Answer 34

1. INCOMPLETE DOMINANCE: red and white snapdragons produce pink offspring. 2. CODOMINANCE: pure red cow, pure white cow → roan cow (speckled) 3. MULTIPLE ALLELES: 3 types of human blood: A, B, O Different types of antigens. 4. SEX LINKAGE: The genes for red-green color vision are found on the X chromosome.

Question 35

Sex linkage

Answer 35

The genes carried on the X and Y chromosomes code for characteristics other than the gender of the individual. 2 of the 46 chromones are sex chromosomes. Most sex link traits tend to be on the X chromosome.

Question 36

Polymermase chain reaction

Answer 36

A technique used to amplify large numbers of copies of a particular DNA sequence using the theory that all life contains material that is unique to the species. Individuals within a species contain unique genetic sequences.

Question 37

Polymerase Chain reaction use

Answer 37

``` Genetic testing. Medical diagnosis. DNA fingerprinting. Cloning. Evolutionary study. ```

Question 38

Multiregional theory evidence

Answer 38

Fossils found outside of Africa date before the proposed second wave. Skeleton ‘Mungo man’ is not descended from mitochondrial Eve but is anatomically identical to H. Sapiens.

Question 39

Out of Africa evidence

Answer 39

mtDNA molecular clock evidence suggests maternal inheritance from African Eve. The greatest variety in mtDNA is in Africa. - other population groups only contain a subset of diversity.