Unit 2 - Multicellular organisms Flashcards
The basic unit of living things
Cells
An organism composed of many cells
multicellular
An organism composed of only one cell
unicellular
A group of similar cells (e.g. muscle cells) specialised for the same function
Tissue
Term for cells that do not yet have a function
non-specialised, or unspecialised
Several tissues working together to carry out a single function (e.g. heart)
Organ
Alternative name for cell division which provides new cells for growth and repair
Mitosis
Cells in animals that have a specific function
Specialised
Areas in plants that are the site of mitosis
Meristems
Where are the locations of meristems in plants?
Root tips and shoot tips
What is the purpose of meristems in plants?
Growth and repair
The brain and spinal cord make up
The central nervous system (CNS)
Part of the brain responsible for conscious thought, emotions and memory
Cerebrum
Area of the brain which controls balance and muscle co-ordination
Cerebellum
Part of the brain that controls breathing and heart rate
Medulla
Neuron that carries a electrical impulse from a receptor to the CNS
Sensory neuron
Neuron that carries an electrical impulse from CNS to a muscle or gland
Motor neuron
Fast response to danger
Reflex action
Order of a reflex action (three neurons involved)
Sensory neuron to relay neuron to motor neuron
A tiny gap between two neurons
Synapse
Type of message that travels across a synapse
Chemical
Glands that make and release hormones
Endocrine glands
Transports hormones from a endocrine gland to a target organ
Blood
Protein on the surface of a target cell that is complementary to a hormone (receptor)
Receptor
Organ that detects changes in blood glucose
Pancreas
If glucose increases in the blood, this hormone is produced by the pancreas
Insulin
If glucose decreases in the blood, this hormone is produced by the pancreas
Glucagon
Name of organ that stores glucose as glycogen
Liver
Term for the control of blood glucose
Regulation
Health condition due to failure to release insulin
Diabetes
Molecule made by joining many glucose molecules together
Glycogen
Biological term that means a double set of chromosomes
Diploid
Biological term that means a single (one) set of chromosomes
Haploid
Alternative name for sex cells
gametes
Female gamete in plants
Ovule
Male gamete in plants
Pollen
Gamete that has a tail to swim in search of female gamete
Sperm
Larger human gamete that has a food store for the development of a zygote
Egg
Part of the flower that makes pollen
Anther
Animal organ that produces sperm
Testes
Animal organ that makes eggs/ova
Ovary
Part of the flower that produces ovules
Ovary
Process of the fusion of male and female gametes
Fertilisation
First cell produced by fertilisation
Zygote
Differences between all the individuals in a species
Variation
Type of variation where there are two or more distinct groups (eye colour, blood type)
Discrete variation
Type of variation with a wide range of values (Height, hand span)
Continuous variation
Example of discrete variation
Gender OR Finger prints OR
Handedness OR Tongue rolling OR
Blood groups
Example of continuous variation
Height OR Weight OR Leaf width
OR Hand span OR Seed size
Short section of a chromosome that codes for a characteristic
Gene
Term for several (more than one) gene working to produce continuous variation
Polygenic
Different forms of a gene
Allele
The appearance of an organism for a characteristic
Phenotype
Alleles an organism has for a particular characteristic (usually written as BB, Bb, bb)
Genotype
Allele whose effect always shows when present (BB, Bb)
Dominant
Allele which is not dominant and only shows when dominant allele is not present (bb)
Recessive
Both alleles for a characteristic are the same (BB or bb)
homozygous
Alleles for a characteristic are different (Bb)
Heterozygous
Symbol or letter for parents in a genetic cross
P
Symbol for the first generation in a genetic cross
F1
Symbol for Second generation in a genetic cross
F2
Phenotype ratio from a cross between a heterozygous parent (Bb)
and a homozygous recessive parent (bb)
1:1
Phenotype ratio from a cross between two heterozygous parents
3:1
The number of 120 Drosophila flies from two heterozygous
parents that would be predicted to have the recessive characteristic
(3:1 ratio)
30 have recessive characteristic
The number of 400 pea plants from a cross between a
heterozygous tall plant and a dwarf pea plant (double recessive)
that would be expected to be tall
(1:1 ratio)
200
The reason why the predicted and
the actual results from a genetic
cross are often not the same
Fertilisation is a random process
Reason plants need to transport water from roots to leaves
Photosynthesis OR replacing water Or Transporting minerals
Name of leaf cells that carry out photosynthesis
Palisade mesophyll cells
Specialised root cells
Root hair cells
Biological term for loss of water from root to leaves
Transpiration
Thin layer of waterproof cells on top and bottom of leaf
Epidermal cells
Small pores in leaf that allow gas exchange
Stomata
Cells that control opening and closing of stomata
Guard cells
Vessels that transport water in a plant
Xylem
Chemical or molecule that provides support in xylem vessels
Lignin
Living cells that transport sugar in a plant
Phloem
What transports nutrients. oxygen and carbon dioxide around the body
Blood
Pumps blood around the body
The heart
Side of the heart that contains deoxygenated blood
Right
The side of the heart that contains oxygenated blood
Left
Where deoxygenated blood becomes oxygenated
Lungs
Thin walled top chambers of the heart
Atrium / Atria
Thick walled chambers at the bottom of the heart
Ventricles
Prevents the back flow of blood
Valves
Blood vessel that brings blood FROM the body to the right atrium
Vena Cava
Blood vessel that transports blood from right ventrical to the lungs
Pulmonary artery
Blood vessel that transports blood from the lungs to the left atrium
Pulmonary vein
Blood vessel that transports blood from left ventricle to the body
Aorta
Blood vessel that provides heart muscle with oxygen
Coronary artery
Blood vessels with thick muscular walls that carry blood under high pressure
Arteries
Blood vessels with thin walls and valves that carry blood under low pressure
Veins
Blood vessels that are one cell thick that allow fast exchange of materials with cells
Capillaries
What characteristic make capillaries good at exchanging materials with cells?
Thin walled
Large surface area
Chemical in red blood cells that attract oxygen molecules
Haemoglobin
Molecule formed when haemoglobin combines with oxygen
Oxyhaemoglobin
What lines the trachea (windpipe)
Cartilage rings
Parts of the lungs where gases are exchanged
Alveoli
Molecule that diffuses from blood into lung alveoli
Carbon dioxide
Molecule that diffuses from alveoli into the red blood cells
Oxygen
Features of alveoli that make them efficient for gas exchange
Large surface area
Good blood supply
Thin walls
Traps dirt and microorganisms in the lung airways
Mucus
Sweeps mucus and trapped dirt out of the lung airways
Cilia
Muscular contractions that move food through the digestive system
Peristalsis
Structures in the small intestine that absorb broken down nutrients
Villi
Characteristics of the villi in the small intestine making them efficient at absorbing food molecules
Large surface area
Good blood supply
Thin walled
Molecules absorbed by capillaries in small intestine villi
glucose and amino acids
Part of the villi that absorb fats
Lacteal
Molecules absorbed by lacteal in small intestine villi
Broken down fats
Biological terms for the process of cell division
Mitosis
Two sets of matching chromosomes
Diploid
Structures which carry genes and are found in the nucleus
Chromosomes
Identical copies of a chromosome produced by replication that are joined together
Chromatid
Centre of a cell where chromosomes line up
Equator
Fibres which separate and pull chromatids to opposite poles
Spindle fibres
What is the function of mitosis?
Provide new cells for growth and repair
