biology

Question 1

what is meiosis

Answer 1

cell division that produces gametes with half the number of chromosomes

Question 2

nucleotides

Answer 2

building blocks of dna
consist of:
phosphate
deoxyribose sugar
nitrogen rich base

Question 3

chromosome replication

Answer 3

two chromatids r formed joined in the centre by a centromere

Question 4

frameshift mutations

Answer 4

insertion or deletion of 1 or more bases
information gets jumbled and cannot be read to make protein

Question 5

DNA replication

Answer 5

1)parent DNA molecule unzips
2) copying of dna molecule begins with complementary bases attaching to both strands of DNA
3)replication results in 2 identical double helix’s of DNA

Question 6

complementary base pairing

Answer 6

bases that form the rungs of DNA ladder
(adenine, thymine)
(guanine, cytosine)

Question 7

heterozygous

Answer 7

2 different Alleles

Question 8

mutations

Answer 8

mistake that happens as DNA is copied causing a change to the base sequence

Question 9

triplet code

Answer 9

3 consecutive nucleotides that function as part of the genetic code for the productions of protein

Question 10

phenotype

Answer 10

observable characteristics of an individual
the way a genotype is expressed

Question 11

chromosome

Answer 11

thread like structure in nucleus composed of DNA and proteins
contains genetic information in form of genes

Question 12

genotype

Answer 12

genetic information carried by an individual

Question 13

gene

Answer 13

specific sequences of DNA found in chromosome that carries the genetic code for a particular characteristic

Question 14

alleles

Answer 14

different forms of the same gene located at the same point of homozygous chromosomes

Question 15

silent mutation

Answer 15

changes in genetic code that DONT affect individual

DNA strand is changed but does not affect protein

Question 16

missence mutation

Answer 16

changes that don’t stop the gene from making protein

different protein produced

not function correctly cause diseases

Question 17

nonsense mutation

Answer 17

cells stop reading information on gene

protein is incomplete

cannot function at all

Question 18

homozygous

Answer 18

having 2 identical alleles

Question 19

mitosis functions

Answer 19

growth
wound tissue repair
asexual reproduction
unicellular organisms

Question 20

mitosis

Answer 20

cell division that produces 2 identical daughter cells

Question 21

mitosis stages

Answer 21

interphase: chromosomes replicate to 2 chromatids
prophase: chromatids become visible
metaphase:line up along equator of cell
anaphase: chromatids seperate and move to opposite poles
telophase: 2 nuclei form some number of chromosomes as parent cell
cytokinesis: cell membranes form making 2 daughter cells each with a nucleus

Question 22

meiosis stages

Answer 22

metaphase1: replicates chromosomes form homologous pair attached to spindle fibre and line up in the middle
anaphase1: 1 replicated chromosome of each pair moves to each pole
telophase1: 2 cells are formed each with 1 replicated chromosome
metaphase2: line up on equator attached to spindle fibres
anaphase2: chromatids seperate and move to poles
telophase2: 4 cells results with one copy of each chromosome

Question 23

plant and animal cell difference

Answer 23

plant cell:
cell wall
vacuole
chloroplast

Question 24

role of nucleus in cell

Answer 24

storing of genetic information and cell’s control center. DNA replication, transcription, and RNA processing all take place within the nucleus

Question 25

mitochondria

Answer 25

cellular respiration organelles act like a digestive system which takes in nutrients, breaks them down, and creates energy rich molecules for the cell.

Question 26

ribosomes

Answer 26

build protein

Question 27

cytoplasm

Answer 27

The cytoplasm is the gel-like fluid inside the cell. It provides a platform upon which other organelles can operate within the cell. All of the functions for cell expansion, growth and replication are carried out in the cytoplasm of a cell.

Question 28

cell wall

Answer 28

The cell wall is the protective, semi-permeable outer layer of a plant cell. A major function of the cell wall is to give the cell strength and structure, and to filter molecules that pass in and out of the cell.

Question 29

cell membrane

Answer 29

separates the interior of the cell from the outside environment.

Question 30

vacuole

Answer 30

Vacuoles are storage organelles that usually carry food molecules or wastes in solution