[DSE生物2018］Bio討論區

打錯 係low oestrogen level inhibits FSH secretion
依句啱唔啱？
下面嗰句起pp見到 同concept contradict咗 唔係幾明

唔啱。呢句喺邊年見到?

11年a level
唔係low oestrogen level inhibit, high oestrogen level stimulates咩

你應該咁諗: 當estrogen act alone，estrogen係會stimulate FSH & LH secretion; 當estrogen act together with progesterone, estrogen (together with progesterone)係會inhibit secretion of FSH & LH

After ovulation, yellow body secretes a lot of estrogen and progesterone, which inhibits FSH & LH secretion.

FSH stimulates oestrogen secretion.

Before ovulation, the rise in estrogen will exert positive feedback to stimulate FSH secretion. (Positive feedback means if there's more estrogen, FSH secretion will increase, which then stimulates more estrogen secretion, and then goes on and on...).

Agger

唉 我想攞個3啫 好辛苦啊😭

1 chromatin = 1 DNA?

其實進化係咪一定涉及自然選擇同競爭？

應該唔一定涉及competition掛，我估
例如天災搞到某啲物種死有啲冇死，從而有natural selection，果啲物種之間未必有competition
不過你都係等Merlot巴答好啲

自然選擇 or競爭？
令population有selection pressure

Chromatin 係個structure of chromosome
Chromosome 係由DNA coil 落nuclear protein到組成
DNA係由兩條polynucleotide chain組成
一條polynucleotide 係由大量nucleotide 組成

我諗essential未必係key word
我當年係寫"Compare the base sequence of the DNA of the same gene among the animals." 有一分。不過都係問返有去改卷嘅人好啲

根據marking個biochemical composition個句你個答案可以
但實際上唔啱
因為話明Similar protein 永遠都有similar amino acid
人類harmoglobin 同nitrogen fixing bacteria嘅oxygen binding protein都係analog 唔代表有close phylogenetic relationship

Evolution of new dominant trait in a population 係一定要講到有selective pressure 但可以係artificial / natural
跟住令有trait嘅生物有survival advantage 所以會勝出competition 從而變dominant allele

speciation算唔算進化?
如果speciation resulted from geographical barrier應該可以無competition?

想問一問點解curvature is cornea 會令到有maximum convergence of light 而唔係lens 引致

我會寫曬兩個
不過我估會落alternative marking i guess

基本上marking scheme已經係簡化左好多
dse改卷要開2次會討論
有d咩point可以比分有咩唔比得
基本上而家寫到d似係岩既野已經有分

分享下發生係我身上bio例子
以前有一排個肚痛到想死 (係超級痛果隻), 持續左幾個月
有時仲會嘔出黎, 但嘔出黎既野唔係酸性
買過enzyplex易消達都無用 (成份有amylase, pepsin, protease, vitamin b complex等)
比醫生開抗胃酸藥, 痛多兩錢重 (講左嘔出黎d野唔係酸都照開抗胃酸 )
之後改為針對胃酸不足, 用胃酸supplement (betaline hcl, over-the-counter的)而家叫無事

我睇過下考評局公開的一份5分sample, 其實比分真係好鬆手 而家考bio有general concept重要過操past paper好多.

我考果個年代, 串錯字已經無分