Biology Unit 1 & 2

Haploid

An organism or cell having only one complete set of chromosomes.

Diploid

(genetics) an organism or cell having two sets of chromosomes or twice the haploid number

Prokaryotic cells

(Bacteria) small and simple cells with no membrane bound organelles, 70s ribosomes

Eukaryotic cells

complex, have membrane bound organelles, cater for animal and plant cells

Passive transport

don't require energy

• diffusion

• simple diffusion

• facilitated diffusion

• osmosis

Active transport

require energy

• active transport

• bulk transport

• endocytosis

• exocytosis

Simple diffusion

movement of a solute from an area of high concentration to an area of low concentration

Facilitated diffusion

movement of a solute from an area of high concentration to an area of low concentration through proteins channel

Osmosis

high concentration of water molecules to an area of low concentration, through a semi permeable membrane

Endocytosis

large particles enter the cell actively

Exocytosis

large particles leaving the cell actively

Phagocytosis

when solids are taken into a cell by endocytosis

Pinocytosis

when fluids are taken into a cell by endocytosis

Surface area : volume ratio

The smaller the cell, the larger the SA:V ratio

Crenation

an animal cell losing water

Cytolysis

when water moves into an animal cell and there's too much of liquids, it bursts

Plasmolysis

when plant cells lose water

The plasma membrane is mainly composed of 2 chemicals:

phospholipids and proteins

What explains the nature of the plasma membrane?

fluid mosaic model

Turgid

when the plant cell takes solution and becomes tight with it

What is a polymer made of?

a large number of monomers

What is a monomer of DNA called?

nucleotide

What are the 3 components of a nucleotide?

phosphate group, pentose sugar, a nitrogen base.

the nitrogen bases consist of:

• adenine

• guanine

• thymine

• cytosine

What breaks the bond in DNA for replication?

DNA helicase

What enzyme makes a new strand for replication? (only from 3' to 5')

DNA polymerase

Okazaki fragments

small fragments of DNA produced on the lagging strand during DNA replication, joined later by DNA ligase to form a complete strand.

Centripetal

In animal cells the cleavage furrows from the outside of the cell and moves towards the center

Centrifugal

In plant cells, the cell plate forms in the center and moves laterally

Intrinsic pathway

also called mitochondrial pathway: moves from the inside of the cell to out

Extrinsic pathway

also called the death ligand pathway: from outside of the cell (when the message ball reaches the receptor)

Three types of potency in stem cells

totipotent, pluripotent and multipotent

Tissue

a collection of cells

Organs

a collection of tissues

Systems

a collections of organs

Xylem

transports water and minerals from roots to leaves

Phloem

transports organic food to each and every cell in the plant (translocation)

Homeostasis

maintaining the internal environment through narrow limits

examples=body temperatures, blood glucose, ph, salts, water

Nephron

basic unit of a kidney

Physical digestion

physically broken down by chewing or mastication

Chemical digestion

food is broken down using chemicals (enzymes)

Stomata

tiny pores on the leaves for gas exchange. opens during the day to absorb sunlight, closes during the night

Type 1 diabetes

when the pancreas produces little or no insulin.

Hyperglycemia

high blood sugar

Hypoglycemia

low blood sugar

Negative feedback loop

when something causes disruption to homeostasis, the "nfl" brings a system closer to stability or homeostasis

Endocrine system

responsible for the production and secretion of hormones which control and regulate bodily processes

Glands in the Endocrine system

• pituitary gland

• hypothalamus

• pineal gland

• thyroid and parathyroid

Excretory system

removes substances from the blood through excretion, also helps control of water in the body

Digestive system

breaks down food and processes food to be used by the body

Parts of the Digestive system

stomach, liver, pancreas, small and large intestine

Alpha cells

secrete glucagon

Amensalism

-/+

one species is harmed while the other is not affected

Antidiuretic hormone (ADH)

secreted by the posterior pituitary gland in response to high solute concentrations in the blood

Apoptosis

controlled death of cells in the body

Autosome

any chromosome that is not a sex chromosome

Behavioral adaptation

evolved modifications to an organisms actions

Beneficence

ethical concept to maximize benefits

Beta cells

cells that secrete insulin

Binary fission

cell replication used by prokaryotes

Blebbing

budging of plasma membrane to from apoptotic bodies

Carrier

organism who has inherited a copy of the recessive gene, but doesn’t display it

Caspases

enzyme for apoptosis

Centrioles

structures composed of proteins which make the spindle fibers in mitosis and meiosis

Centromere

structure which holds sister chromatids together

Chloroplast

site of photosynthesis

Chlorophyll

green pigment responsible for absorbing light in photosynthesis

Co dominance

where both alleles are dominant and expressed

Commensalism

+/0

one gains benefit, other unaffected

death receptor pathway

pathway for apoptosis

hyperglycaemia

state of having blood glucose levels above the normal range

hyperthyroidism

overactivity of the thyroid gland, resulting in increased production and secretion of thyroid hormones

hypoglycaemia

state of having blood glucose levels below the normal range

keystone species

species whose effects on an ecosystem are greater than expected relative to its population size

lysosome

It contains digestive enzymes, they are responsible for breaking down cell waste

Nephron

unit of the kidney

polyploidy

when an organism contains additional sets of chromosomes in its genome

somatic cell nuclear transfer (SCNT)

transference of a somatic cell nucleus into an enucleated egg cell

totipotent

stem cells which can differentiate into any cell type

Bioethical concepts

• non maleficence

• beneficence

• justice

• integrity

• respect