Paper 1 Flashcards
What makes up a nucleus?
23 pairs of chromosomes.
What are chromosomes made out of?
DNA molecules.
What happens in Stage 1 of the cell cycle?
The longest of the three stages, cell grows gaining mass, increases number of sub-cellular structures, DNA replicates & forms two copies of each chromosome.
What happens in Stage 2 (mitosis) of the cell cycle?
One set of chromosomes is pulled to each end of the cell, nucleus divides in two
What happens in Stage 3 of the cell cycle?
Cytoplasm and Cell membranes divide, 2 identical cells are formed
What are three reasons for the cell cycle?
Development, Growth, Repair
What does Differentiation mean?
Acquiring different sub-cellular structures. Examples: Nerve cells, muscle cells, red blood cells.
What are the two reasons for stem cells?
1) Differentation, 2) It is capable of giving rise to any other stem cells
What is an embryonic stem cell?
Embryonic stem cells surrounded by an embryo, function is to differentiate making all of specialized cells of the body.
Embryotic stem cells can make….
almost every cell in the body.
Stem cells are found in the ____ of plants.
Root cells
Stem cells are found in the ____ of animals.
Bone marrow
What are three uses for stem cells in plants?
Cloning plants quickly and economically, Genetically identical plants for research, Cloning of crops with special features.
Adult stem cells have a high risk of…
Carrying viruses.
How do Bacteria multiply?
Loop of DNA replicates, two copies move apart to each end of cell, cytoplasm divides and new cell walls form, eventually splitting into two.
Binary fission means..
splitting in two (eg, bacteria multiplication)
Osmosis is specifically…
The movement of water.
What does Osmosis move through?
Partially permeable membranes from an area of high concentration to low concentration.
Active transport moves across a…
Membrane from an area of low to high concentration.
What is a tissue?
One type of cells carrying out a function.
What is an organ?
Made up of different tissues, carries out joint function.
What is an organ system?
Group of organs that carry out a function.
What are the organs/parts of the digestive system
Mouth, Salivary Gland, Aesophagus, Gall bladder, Stomach, Pancreas, Small intestine, Large intestine, Rectum
What does the a) mouth b) Salivary gland c) Liver do?
a) Mechanical breakdown b) Produces amylase c) Produces bile
What does the a) gall bladder b) small intestine c) stomach do?
a) stores bile b) moves glucose, ions etc to blood large surface area d) churns up food, stomach acid (HCl) kills bacteria, provides environment for protease to work
what does the a) pancreas b) large intestine c) anus do?
a) Produces enzyme b) removes excess water c) gets rid of waste food
What is a lipase and what does it do?
Breaks down fats into fatty acids, made in pancreas and small intestine & works in small intestine
What is Protease? and what does it do?
Breaks down proteins into amino acids, made in stomach & pancreas & small intestine, works in stomach and small intestine
What is amylase and what does it do?
Breaks down starch into sugars, made in salivary glands & pancreas & small intestine, works in mouth & small intestine
What is the lock and key mechanism?
Enzyme with very specific active site forms enzyme-substrate complex and either break apart products and release or join products and release
How does temperature affect enzyme activity?
Any temperature below optimal temp not have enough energy, any too high makes enzyme denatured (not killed)
How does pH affect enzyme activity?
Denatured in both ways unless optimal.
What makes up the respiratory system?
Mouth, Branchus, Branchide, Alveoli, Diaphragm, Aesophagus, Trachea, Lung, rib, intercastal muscle, heart.
What is/does the a) Branchus b) Branchide c) Alveoli do?
a) Branch of brachea b) branch of branchus c) Where gas exhange happens, large surface area
What is/does the a) Diaphragm b) trachea c) ribs do?
a) moves up and down to bring air in and out, b) the wind pipe c) protects lungs
What does the a) intercostal muscle b) heart do?
a) Allows ribs to expand b) Pumps blood
What is the cardiovascular system? how does it work?
Heart system, double system= blood gets pumped to heart, then lungs, then back to heart, then rest of body.
What are the parts of the heart?
Vena Cava, Right abraum, Right ventricle, Pulmonary artery, Pulmonary vein, Left atrium, left ventricle, actra
Where does everything in the heart go?
VRRPPLLA (read what are parts of heart answer to understand) (yes in that order)
Which part of the heart has a larger muscle?
Left, carries blood to rest of body, Right only has to carry to lung.
What does Pulmonary veins carry?
Unoxygenated blood.
What walls are thicker, Capillaries, Arteries or Veins?
Arteries
What is a thin lumen?
the hole inside of an artery.
Which one of these are one cell thick for diffusion: Capillaries, Arteries or Veins?
Capillaries
What do Veins carry and what are their key features?
Deoxygenated blood, Have valves and thin walls.
What is a serum?
Natural, liquid blood without blood cells.