Mental exam all

what is a reactant

a starting substance that undergoes a chemical change during a chemical reaction

what is a product

a substance formed as a result of a chemical reaction

what is a metal

elements on the left-hand side of the periodic table, they are malleable, lustrous and conductive. they also are cations

what is a non-metal

elements on the right side of the periodic table

what is a ion

an atom that is charged because it has an unequal amount of electrons and protons

what is a cation

a positively charged ion that results from an atom loosing electrons.

what is a anion

a negatively charged ion formed when an gains electrons

what is a soluble solution

a mixture where a substance (the solute) completely dissolves into a fluid (the solvent) to create clear mixture with no precipitate

what is a insoluble solution

a substance (solid) that will not dissolve into a solvent and instead becomes a sediment

what is precipitate

a solid, insoluble compound formed in a precipitation reaction

what is a aqueous solution

a mixture where a substance (the solute) is dissolved in the solvent (usually water)

what is noble gases

the stable gaseous elements in group 18 of the periodic table

what is an ionic bond

a bond between a negativly charged anion and a positively charged cation

what is a ionic compound

a substance made up of negatively charged anion and positively charged cation.

what is a precipitation reaction

a reaction used to produce solid products from solutions of ionic substances

what is a double displacement reaction

when two reactants exchange ions to perform new products during a chemical reaction

what is a solution

a mixture of a solute dissolved in a solvent

what is Asexual reproduction

a type of reproduction in which one parent produces offspring that are all genetically identical to the parent

what is genetic material

information that is stored in DNA and passed onto the next generation by asexual or sexual reproduction

what is offspring

new organisms that are produced by asexual or sexual reporoduction

what are some of the pro’s and con’s

for asexual reproduction

pros are only needs one parent, doesn’t take much energy, and it is fast, con’s are it has the same DNA as it’s parent so it can’t adapt to new environments well from traits it might have gotten from the other parent, they are all genetically the same so if a virus comes around it has a chance of wiping out an entire population

what is binary fission

a form of asexual reproduction used by bacteria (parent cell splits into two parts)

what is parthenogenesis

asexual reproduction where an egg develops WITHOUT fertilisation

what is fragmentation

asexual reproduction that occurs when a new organism grows from a fragment of another

what are all the types of Asexual reproduction

binary fission, parthengenesis, and fragmentation

what is sexual reproduction

type of reproduction in which two parents produce offspring that are genetically different to the parents; the fusion of gametes from two parents

what are some of the pros and cons for sexual reproduction

pros are more genetically diverse, can adpat to new environments, more immune to illness, cons are needs two parents, takes more energy, slower process

what is fertilisation

the process where two gamets (sex cells) fuse to produce a signle cell

what are all the types of fertilisation

external, internal

what is external fertilisation

when the egg and sperm meet outside the bodies of the parents - in water

pros and cons of external fertilisation

pros are more eggs are laid, low parental energy, the mother doesnt have to carry the children so can reproduce more quickly again, cons are lower chance of survival and the eggs might not meet the sperm, egg and sperm wastage, less protected out in the open

pros and cons for internal fertilisation

pros are higher success rate, is more protected in the mother stomach, better parental care. cons takes more energy from the parents, fewer offspring porduced, takes more time

what are r-strategist

organisms living in unstable environmets that breed rapidly

k- strategists

are organisms living in stable environments who breed carefully

what organisms are likely to recieve more parental care and why

k-strategists as there are fewer born in a more controlled enviroment which means the parents are able to take care of them better.

which organism is more likley to be independent

r- strategist as they don’t receive much parental care and must learn how to survive in more unstable environments on their own

how do plants reproduce asexually

producing genetically identical clones from a single parent without gamete fusion,

how does cross pollination work

the pollen from one plant attaches to the stigma and digs a pollen tube down to the ovary, and then transfers the pollen to the stigma. Pollen lands on stigma- Grows a pollen tube down to ovary- Sperm travels to fertilise egg

what is pollination

transfer of pollen from anther to stigma

what are gamets

sex cells (egg in girls, sperm in guys)

what are clones

an organism that is genetically identical to another

what is mitosis

the process of cell division that results in gentetically identical daughter cells- creating the same cell for growth or repair

what is cytokinesis

the splitting of a replicating cell into two cells

what are somatic cells

the body cells exept gamets

what is interphase

a phase of a cell life where normal functioning occurs

what are the stages of the cell cycle

interphase prophase, metaphase Anaphase, telophase cytokines,

why does the the rate of mitosis need to be controlled

becuase cells do not last forever and need to be programed into a cell’s DNA, when something goes wrong this can cause mutagens that can lead to cancer

what is a diploid

it contains two sets of complete chromosomes

why is cell division important

so they can grow or repair damage

what is interphase

normal life of the cell

what is prophase

chromosomes apear, nucleus membrane disappears, spindle forms,

what is metaphase

chromosomes line up in a sigle line across the center with spindle fibres attached to the centromere

what is Anaphase

each pair of chromatids seperate at the centromere, each chromatid moves to the side,

what is telophase

necear membrane re-forms

what is cytokinesis stage

cytoplasm divides (two daughter cells are produced)

what is a haploid

it contains one complete set of chromosomes in each cell eg gamets

what is meiosis

the process that results in the formation of gametes with half of the genetic material of the parent cell

what happends in fertilisation interms of the gametes

Gametes contain 23 chromosomes, made up of 22 autosomes (chromosome thats not a sex cell) and 1 sex chromosome (X or Y), which combine during fertilisation to restore the full number of 46 chromosomes. due to this everytime the order of the chromosomes in the egg or sperm will always be different which how siblings look different

what is the process of Meiosis

phrophase I, Metaphase I, Anaphase I, Telophase I and cytokinesis , Phrophase II, Metaphase II, Anaphase II, Telophase II and cytokinesis

Prophase I

Chromosomes condense and become visible. Homologous chromosomes pair up (synapsis) to form tetrads. Crossing over occurs where DNA is exchanged between chromosomes. Nuclear membrane breaks down and spindle fibres form.

Metaphase I

Tetrads line up along the middle (equator) of the cell. Spindle fibres attach to homologous chromosomes. The orientation is random (independent assortment).

Anaphase I

Homologous chromosomes are pulled apart to opposite poles of the cell. Sister chromatids remain joined together.

Telophase I & Cytokinesis

Chromosomes reach opposite ends. Nuclear membranes may reform. The cell divides into two haploid cells (each has half the number of chromosomes).

what happends in prophase II

two daughter cells will be in the new cell the spindle fibres wil start to get ready

what happends in Metaphase II

Chromosomes line up at the equator. Spindle fibres attach to the centromeres of sister chromatids.

what happends at Anaphase II

Sister chromatids are separated and pulled to opposite poles of the cell.

what happends at telophase II and cytokinesis

Chromosomes reach the poles, Nuclear membranes reform. Cells divide, resulting in four genetically different haploid cells.

what is fertilisation in plants

fusion of gametes (happens after pollination)

Where is DNA found in a eukaryotic cell?

In the nucleus (also small amounts in mitochondria).

What structure in the nucleus contains DNA?

Chromosomes

what are chromosomes

a piece of DNA

What is the shape of DNA called?

double helix.

What does the DNA double helix look like?

two polynucleotides that are twisted hecically around each other- resembles a ladder

What forms the sides of the DNA “ladder”?

Sugar and phosphate molecules.

What forms the rungs of the DNA “ladder”?

Nitrogen bases.

What is a nucleotide?

a subunit of a nucleic acid (they are the building blocks of DNA)

how many chromosomes do humans have

46 in total, 23 from your mum, 23 from your dad

what are the three parts that make up a nucleotide

sugar with a deoxyribose base, phosphate group, and a nitrogen base

what are the four nitrogen bases in DNA

Adenine, thymine, cytosine, guanine,

what is the base pairing rule

Adenine pairs with thymine, cytosine pairs with guanine

why is the base pair rule important

it ensures accurate DNA replication

what is a polynucleotide chain

when nucleotides join together by their sugar and phosphate groups to form a long chain

why are the hydrogen bonds weak

so they can be broken so the stand can be unwound and coppied

what are DNA two vital properties

making copies of itself, and carry information the oder of bases along a strand is a code fro making protiens

what are chromosomes made up of

DNA molecules tightly wound around proteins

what are genes

a DNA sequence based of nucleotide base pairs that form all your traits

where are genes located

along eacg length of a chromosome, in a specific position

what does mRNA stand for

messanger RNA

where is mRNA found

made in the nucleus and moves to the cytoplasm

wht is the role of mRNA

it carries the genetic instuctions from DNA to the robosomes

how do genes make protein

the DNA molecule unwinds and one stranct as a patterns to form a molecule of mRNA which then coppies the code

what does tRNA stand for

transfer RNA

where is tRNA found

in the cytoplasm

what is the role of tRNA

brings amino acids to the ribosome during protien synthesis

what does RNA consist of

ribose sugar, a nitrogen base - adenine, cytosine, guanine, uracil

what is an allele

a different version of the same gene

what is transcription

the process where DNA is coppied into mRNA

where does transcription occur

in the nucleus

what is translation

the process where mRNA is used to build a protien

where does translation occur

at the bibsome in the cytoplasm