Nucleic acid và gene

Home Lớp 9 Khoa học tự nhiên 9 - sách kết nối tri thức Bài 38: Nucleic acid và geneBài tập nâng cao

{"common":{"save":0,"post_id":"8311","level":3,"total":10,"point":10,"point_extra":0},"segment":[{"id":"9641","post_id":"8311","mon_id":"1159533","chapter_id":"1159673","question":"M\u1ed9t gene có 480 adenine và 3120 liên k\u1ebft hydrogen. Gene \u0111ó có s\u1ed1 l\u01b0\u1ee3ng nucleotide là:<\/p>","options":["A. <\/strong>1200","B.<\/strong> 2400","C.<\/strong> 3600","D. <\/strong>3120"],"correct":"2","level":"3","hint":"- M\u1ed9t liên k\u1ebft hydro hình thành gi\u1eefa các c\u1eb7p base: A-T (2 liên k\u1ebft hydro) và G-C (3 liên k\u1ebft hydro).<\/p>- T\u1ed5ng s\u1ed1 nucleotide trong gene là t\u1ed5ng s\u1ed1 c\u1ee7a t\u1ea5t c\u1ea3 các base (A, T, G, C).<\/p>","answer":"\u0110áp án \u0111úng: B. 2400<\/strong><\/span><\/p>- Adenine (A)<\/strong> = 480 → Thymine (T)<\/strong> = 480 (do A-T ghép \u0111ôi). - T\u1ed5ng liên k\u1ebft hydro t\u1eeb A-T: 480 × 2 = 960<\/p>- T\u1ed5ng liên k\u1ebft hydro là 3120. Ph\u1ea7n còn l\u1ea1i t\u1eeb G-C: 3120 − 960 = 2160<\/p>- M\u1ed7i c\u1eb7p G-C t\u1ea1o 3 liên k\u1ebft hydro → S\u1ed1 c\u1eb7p G-C: 2160 \/ 3 = 720 - S\u1ed1 nucleotide G và C: 720 + 720 = 1440<\/p>- T\u1ed5ng nucleotide: A + T + G + C = 480 + 480 + 720 + 720 = 2400<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"127","test":"0","date":"2025-01-10 22:25:53","option_type":"txt","len":0},{"id":"9642","post_id":"8311","mon_id":"1159533","chapter_id":"1159673","question":"M\u1ed9t gene có chi\u1ec1u dài 3570 Å. Hãy tính s\u1ed1 chu kì xo\u1eafn c\u1ee7a gene?<\/p>","options":["A. <\/strong>210","B.<\/strong> 119","C.<\/strong> 105","D. <\/strong>238"],"correct":"3","level":"3","hint":"- Xem xét m\u1ed1i quan h\u1ec7 gi\u1eefa chi\u1ec1u dài gene và s\u1ed1 chu k\u1ef3 xo\u1eafn c\u1ee7a nó.<\/p>- Nh\u1edb r\u1eb1ng m\u1ed7i chu k\u1ef3 xo\u1eafn c\u1ee7a DNA có m\u1ed9t \u0111\u1ed9 dài nh\u1ea5t \u0111\u1ecbnh.<\/p>- Hãy s\u1eed d\u1ee5ng d\u1eef ki\u1ec7n "m\u1ed7i chu k\u1ef3 xo\u1eafn c\u1ee7a DNA dài 34 Å" \u0111\u1ec3 tính toán.<\/p>","answer":"\u0110áp án \u0111úng: C. 105<\/strong><\/span><\/p>S\u1ed1 chu kì xo\u1eafn c\u1ee7a gen là: 3570 : 34 = 105 (chu k\u1ef3)<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"127","test":"0","date":"2025-01-10 22:27:25","option_type":"txt","len":0},{"id":"9643","post_id":"8311","mon_id":"1159533","chapter_id":"1159673","question":"M\u1ed9t \u0111o\u1ea1n gene có chi\u1ec1u dài 4080Å, A\/G = 2\/3. S\u1ed1 liên k\u1ebft hydrogen là:<\/p>","options":["A. <\/strong>3120","B. <\/strong>6240","C.<\/strong> 3000","D.<\/strong> 3600"],"correct":"1","level":"3","hint":"- \u0110\u1ec3 tính s\u1ed1 liên k\u1ebft hydro (H), b\u1ea1n c\u1ea7n nh\u1edb s\u1ed1 liên k\u1ebft hydro gi\u1eefa các c\u1eb7p base A-T và G-C.<\/p>- S\u1eed d\u1ee5ng t\u1ec9 l\u1ec7 A\/G \u0111\u1ec3 xác \u0111\u1ecbnh t\u1ec9 l\u1ec7 các c\u1eb7p base.<\/p>- S\u1eed d\u1ee5ng chi\u1ec1u dài c\u1ee7a gene \u0111\u1ec3 xác \u0111\u1ecbnh t\u1ed5ng s\u1ed1 c\u1eb7p base.<\/p>- Áp d\u1ee5ng m\u1ed1i quan h\u1ec7 gi\u1eefa s\u1ed1 c\u1eb7p base và s\u1ed1 liên k\u1ebft hydro \u0111\u1ec3 tính k\u1ebft qu\u1ea3.<\/p>","answer":"\u0110áp án \u0111úng: A. 3120<\/strong><\/span><\/p>- T\u1ed5ng s\u1ed1 c\u1eb7p base (N):<\/strong> N = 4080 \/ 3,4 \u200b= 1200 (c\u1eb7p base).<\/p>- T\u1ec9 l\u1ec7 A\/G = 2\/3: <\/strong>G\u1ecdi s\u1ed1 A = 2x, s\u1ed1 G = 3x.<\/p>- T\u1ed5ng s\u1ed1 c\u1eb7p base: 2x + 2x + 3x + 3x = 1200\u2005\u200a=> \u200a10x = 1200\u2005=> \u200ax=120<\/p>+ S\u1ed1 A = S\u1ed1 T = 2x = 240<\/p>+ S\u1ed1 G = S\u1ed1 C = 3x = 360<\/p>- T\u1ed5ng s\u1ed1 liên k\u1ebft hydro (H):<\/strong><\/p>+ A-T có 2 liên k\u1ebft hydro: 240 × 2 = 480<\/p>+ G-C có 3 liên k\u1ebft hydro: 360 × 3 = 1080 - T\u1ed5ng: 480 + 1080 = 3120.480 + 1080 = 3120<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"127","test":"0","date":"2025-01-10 22:31:54","option_type":"txt","len":0}]}